My locker is full of Pinkie and Trixie, I think I've worn a pony shirt on every Civie's day I've attended this year and last year, and of course, references. I do a good Trixie impression (I would hope. It took so long to be able to do her voice) and I dressed as her for Halloween. And I draw ponies instead of doing work. Yet some how no one seems to notice. >.< (I've never met a Brony at my school, but that may be me not talking to anyone ever)
So yea, I'm pretty open about it.